1. Field of Invention
The invention relates generally to watering devices for plants and, more particularly, to hand-held portable watering devices having electrically-driven pump means for dispensing water.
2. Description of Prior Art
There are a number of problems associated with the watering of house plants. House-plant watering is normally accomplished through the use of a pitcher or similar liquid-carrying vessel which is tilted by the user to deliver its contents to the plant. The aforementioned manual watering scheme is not well suited for delivering water to hanging plants or to plants which are situated in an out-of-reach location. The use of a manually-held pitcher has serious disadvantages even in the case of conveniently situated plants which have foliage extending beyond the perimeter of the plant container. In this case, in order to deliver water to the plant container, the user must either penetrate the foliage with the pitcher or position the pitcher directly above the plant container and pour through the foliage. When the user penetrates the foliage with the pitcher, there is a risk of breaking or damaging the plant structure. When water is poured from above, the foliage may deflect the water stream, thus preventing efficient delivery to the plant container and possibly causing damage to surrounding carpets and furniture.
An additional disadvantage attendant to the use of ordinary water containers for plant watering is that the user's ability to control the outflow of water from the vessel decreases as the vessel's contents are used up. When a water container is full, the user need only tilt the container a slight amount in order to deliver water. As the contents of the vessel are used up, the angle of tilt must be dramatically increased in order to deliver the vessel's contents. When a vessel is nearly empty, the user is forced to turn the vessel almost completely upside down in order to deliver its contents. In such exaggerated attitudes, control of the outflow becomes extremely difficult.
The aforementioned drawbacks associated with the use of ordinary water containers for plant watering have given rise to rather intense inventive efforts. In order to provide a watering device which need not be tilted in order to accomplish its intended function, inventors have turned toward the use of electrically-driven pumping means to deliver water from the container. Various schemes have been proposed, most of which employ a motor-driven pump which is positioned above the water container. The positioning of the pumping machinery and batteries above the water container is a compromise solution. It is more desirable, from the standpoint of efficiency, to position the pump beneath the level of the water. Submerging the pump, motor and batteries presents problems which cannot be solved in an economically feasible manner. One problem in particular with such a structure is that the electric motor must be waterproof, including the provision of a waterproof rotary seal on the motor shaft. The expense of this structure precludes its use in reasonably priced home watering devices. Placing the motor, pump and power source above the level of the water solves, or at least lessens, the waterproofing problems. The top-mounted pump arrangement is not only hydraulically inefficient, but takes some time to prime and also causes the watering device to be rather top-heavy.
Other prior art devices use a motor-driven pump to pressurize the air inside the liquid container, thus forcing the liquid out of a dispensing hole. This structure requires the use of an airtight vessel and airtight seals within the pumping unit. The expense of this structure precludes its use in inexpensive home devices. A further disadvantage of the pressurized system is that, unless the seals are perfect, the vessel will depressurize during the long periods of nonuse, thus requiring repressurization during the next use. This often results in an annoying delay during which time the pump is repressurizing the container. The delivery of water is delayed by a period of time dependent upon the vessel's size, pump size, etc.
The watering devices in the prior art are all distinguishable from the instant invention in that none discloses or suggests the structure of the present invention, which provides all of the advantages of a submerged pump without requiring the use of a waterproofed electrical motor or complicated seals.